By the late 1910s, Russia became the hub for the Bolsheviks during the Russian Civil War. The Russian Soviet Federative Socialist Republic would become one of the founding members of the Soviet Union in 1922. Under Vladimir Lenin's policies of national delimitation, the RSFSR gradually began to shrink as new national republics were established (reaching its final borders in the late 1990s). Throughout the Cold War and beyond, Russia developed as one of the industrial centers of the USSR, which was centered primarily along the Volga River and its tributaries. Under the leadership of Boris Yeltsin, Russia would emerge as a sovereign republic within the USSR and would become one of the founding members of a reformed USSR in 1991. The 1990s would become the height of the Parade of Sovereignties movement, in which many areas demanded equality within the USSR. Tatarstan, Tuva, and Vainakhia were the first to be split off from Russia. The Russian Republic reached its current borders in the late 1990s.

The majority of those living in Russia are ethnic Russians. Finns, Tatars, and Ukrainians make up the largest minorities within Russia. Most Russians adhere to the Eastern Orthodox Church, which has slowly been on the rise since the 1990s. Russia has the largest economy within the Soviet Union and dominated by agriculture and industry. In recent years, Russia has emerged as the "tech capital" of the USSR as many manufacturing of electronics have moved into the area. The cities of Nizhny Novgorod and Tolyatti are the automotive capitals of the USSR, with virtually all the major Soviet car companies centered there. In recent decades, Russia has been politically dominated by the Communist Party in the south (the so-called "Red Belt") and the Democratic Party in the north.